Syringe.



PATBNTED DEC. 19, 1905. J. O. BLAIR.

SYRINGE;

APPLICATION FILED 1320.8, 1904.

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UNITED ST ATES PATENT OFFICE.

JOHN OARLISLE BLAIR, OF LOUISVILLE, KENTUCKY, ASSIGNOR ONE- HALF TO THE BLAIR DENTAL MANUFACTURING (30., OF LOUISVILLE, KENTUCKY, A CORPORATION OF KENTUCKY.

SYRINGE.

N0. 807,905. Specification of Letters Patent. Patented Dec. 19, 1905. Application filed c e 8, 1904:- Serial No. 235,944

To all whom y COW/061%! through the tube 2.. Thus the syringe may Be it known that I, JOHN OARLISLE BLAIR, a be operated with great rapidity. It will be citizen of the United States, and a resident of further seen that since the coils or convolu- Louisville, in the county of J efi'ersou and State tions of the spring 3 regularly diminish in 5 of Kentucky, have made certain new and usediameter from the base outward the spring ful Improvements in Syringes, of which the may be compressed flat within the cup-like following is a specification. plate 4:, and hence the bulb 1 may be com- My invention is an improvementin the class pressed as fiat or as fully as if the spring were of syringes having elastic expansible bulbs. absent, as required to fully eject the liquid 10 The construction, arrangement, and operacontained in it and allow corresponding amplition of parts are as hereinafter fully described tude of expansion. and shown in the accompanying drawings, in It will be seen that my syringe has an imwhich portant advantage over the old form in which Figure 1 is a side view of a dental syringe. the screw is provided with a spherical or bulb- 5 Fig. 2 is a sectional side view showing the ous head, and a washer is applied between bulb provided with my expanding attachment. the nozzle and the elastic bulb, since in my The spherical elastic bulb 1 of the syringe case the concavo-convex disks are practically is constructed in the usual way of soft rubber parallel and a comparatively large extent of and adapted for self-expansion, whereby when surface of the same is clamped between the 2 compressed manually it resumes its form with disks, so that leakage is impossible.

greater or less rapidity. This operation takes hat I claim as new, and desire to secure by place quite slowly when the tube, through Letters Patent, is which liquid is drawn in, is' small. This is 1. An improved dental syringe comprising particularly the case in dental syringes, and a tube, an electric bulb attached thereto, two 2 5 it is highly desirable to effect it quickly. To concavo-convex plates arranged within the this end I have provided the bulb 1 with an bulb, and a conical or helical spring arranged expanding member in the form of a spring 3, with its larger end contiguous to the tube, which is formed, arranged, and attached as and its several coils decreasing in diameter follows: The bulb 1 is secured to thetube 2 from the base outward in such degree that 3 by means of two concavo-convex plates 4: and they are adapted to lie one within the other 5, the latter (5) being arranged inside the bulb when the bulb is fully compressed.

and furnished with a hollow screw that passes 2. In adental syringe of the class indicated, through the outer plate 5 and enters the base the combination, with the discharge-tube 2, of the tube 2. By screwing up the latter havingascrew-threaded socket in its base end, 35 tightly the bulb 1 is clamped between the of two concavo-convex plates, one of which is 80 plates 4: and 5, as shown. A small concavoaiiixed to the base of the tube, and the other convex plate 6 is arranged within the bulb 1 arranged parallel therewith and having a 1 directly opposite the plate 4, and a helical screw-threaded tenon adapted to enter the wire spring 3 is interposed. The outer end socket of the tube, and an expansion-bulb F 4 of the spring enters a socket in plate 6, and its which is clamped between the plates, substan- 5 larger end or base portion lies in the concavity tially as described. of plate 4:. It is apparent the spring thus ar- JOHN OABLISLE BLAIR. ranged will greatly aid the bulb 1 in expand- Witnesses: ing after compression, so that water or other LYLE \V. BUTLER, 45 liquid may be quickly drawn into the bulb EDGAR S. INGRUM. 

